Here’s How a Toilet Works

A toilet has more moving parts than just that handle everyone knows about. A toilet integrates water pressure, valves, floats and basic plumbing principles to deliver trouble-free operation — most of the time, that is. Here’s a rundown of the inner workings of a toilet that many people never see.

Shutoff Valve

Located on the wall behind the toilet, this controls water entering the fixture from a household water line.

Fill Valve/Float Assembly

Inside the tank, the fill valve controls the flow of supply water to fill the tank to the proper level. A float switch on an extended arm — or incorporated inside the fill valve itself — senses the tank water level. When the toilet is flushed, the float opens the fill valve to refill the tank, then shuts it when the tank is full.

Overflow Tube

For protection against indoor flooding if tank water level exceeds maximum, water is diverted harmlessly down the overflow tube into the bowl.

Flapper Valve

Installed in the bottom of the tank, the round rubber or plastic flapper valve is opened by the chain attached to the flush handle. A correctly functioning flapper releases about 80 percent of the tank volume into the bowl, effectively flushing waste into the sewer, then closes to allow the tank to refill. Here’s what happen when it doesn’t function correctly:

• If the valve doesn’t open far enough due to slack in the chain, or closes too rapidly, flushing may be weak and ineffective.
• If the flapper sticks wide open — a tangled or snarled operating chain is a frequent cause — the tank fill valve runs continuously until someone jiggles the handle to unstick the flapper.
• If the flapper is worn or deteriorating, it doesn’t seal properly and water seeps from the tank into the bowl, causing the fill valve to intermittently actuate, then rapidly shut off again.

At Sobieski Services, Inc., our goal is to help our customers in Delaware, Pennsylvania, Maryland and New Jersey learn more about energy and home comfort issues — especially HVAC and plumbing issues — so that they can save money and live in healthier, more comfortable homes.

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